Osteogenesis imperfecta in children and adolescents-new developments in diagnosis and treatment

Osteogenesis imperfecta in Peruvian children: Phenotypic and therapeutic insights from a pediatric hospital

Osteogenesis imperfecta (OI) is a genetic disorder of the connective tissue that is characterized by high bone fragility. It has a worldwide incidence of 1 in 10,000. The diagnosis is mainly clinical-radiological. Treatment is based on the use of bisphosphonates and orthopedic surgeries. The objective of this study was to establish the clinical, radiological, and therapeutic characteristics of OI in pediatric patients of a national reference pediatrics institute. This was conducted through a descriptive and retrospective analysis. All patients under 18 years of age with a diagnosis of OI treated at the Instituto Nacional de Salud del Niño de Breña (INSN-Breña) between 2010 and 2021 were included. In total, 91 patients with OI were studied, more than half of whom were male. A total of 93.4% had a history of fractures, 72.5% had blue sclera, 39.6% had bowed legs and 20.9% had dentinogenesis imperfecta. The minimum-maximum value of fractures was 0-18. A total of 75.8% of patients started treatment with bisphosphonates and 41.8% used adjuvant medications. Less than 50% of patients required surgical treatment. Osteogenesis imperfecta is a genetic and chronic pathology. The use of the Van Dijk severity grade and the Aglan severity scale is simple to apply and therefore should be used to improve the classification of groups with the highest risk of fractures and response to treatment. Due to the low incidence of this disease, it is important to raise awareness and increase the research volume on this subject.

Integrative Management of Bone Deformities in Osteogenesis Imperfecta: A Case Report on Zoledronic Acid and Corrective Osteotomy

Osteogenesis imperfecta (OI) is a hereditary genetic condition characterized by brittle bones that are easily broken. Surgical intervention is necessary frequently to treat fractures and deformities in patients diagnosed with OI. In this case, we discuss a case of a nine-year-old male child diagnosed with OI. This boy was previously operated on one year back for a femur fracture with osteotomy and internal fixation with nails, followed by implant removal at a later stage almost one year later. This boy was brought to our hospital with convex deformities of femur and tibia. Upon evaluation and review of this boy's case, the decision was made to administer a zoledronic acid infusion cycle over three days to enhance bone strength. Following this pharmacological therapy, this patient was planned for corrective osteotomy and internal fixation of the femur. This case underscores the complexities of managing OI and also highlights the importance of the therapeutic role of bisphosphonates like zoledronic acid alongside surgical intervention to address these kinds of bony deformities and improve patient outcomes.

Ophthalmological screening guidelines for individuals with Osteogenesis Imperfecta: a scoping review

BACKGROUND

Osteogenesis imperfecta (OI) is a connective tissue disorder in which the Type 1 collagen is defective. The eye is a structure rich in collagen Type 1 and is heavily impacted by the disease. Many vision-threatening eye diseases have been associated with OI. The onset of these diseases also tend to occur at an earlier age in individuals with OI. Despite the research on these risks, appropriate ophthalmological screening or care guidelines for individuals with OI remain unknown. As such, the purpose of this scoping review was to explore and describe existing ophthalmological screening and care guidelines to orient OI patient care.

MAIN BODY

A scoping review based on the Joanna Briggs Institute (JBI) methodology was conducted. A search of databases (PubMed and Medline) was completed in consultation with a research librarian. A total of 256 studies were imported for screening. Primary sources matching the inclusion and exclusion criteria were screened, extracted, and analyzed using Covidence.

CONCLUSION

A total of 12 primary articles met inclusion and exclusion criteria, containing case reports, case series and cohort studies. Despite the risk of blindness associated with the consequences of OI on the eye, the primary literature fails to provide detailed screening and care guidelines aimed at identifying disease early. We provide general recommendations based on the review findings to guide the ophthalmological care of patients with OI and call upon the experts to convene globally to create screening guidelines. Further investigations of ophthalmological screening are warranted to limit these vision-threatening risks with early detection and treatment. Standardized ophthalmological screening guidelines for OI remain an area for research.

The Creation of an Individualized School Plan for Optimal Inclusion of Students with Osteogenesis Imperfecta

AIMS

The aims of this study were to: (1) synthesize existing evidence regarding the integration of students with osteogenesis imperfecta (OI) into the school setting, (2) tabulate existing school integration tools for OI, and (3) create an individualized school plan to facilitate school integration.

METHODS

Guided by the process of developing evidence-informed guidelines, an international, interprofessional, expert task force was convened. The process entailed: (1) reviewing of the literature, (2) developing recommendations, and (3) creating a clinically meaningful, person-focused plan to facilitate the integration and promotion of school inclusivity. The 13-member task force relied on empirical studies, grey literature, and their experiential knowledge (from clinical, teaching or patient experiences) to devise the plan.

RESULTS

Over a series of eight meetings and five drafts, the Task Force prioritized 14 core items for inclusion. These items consisted of general student information, fracture response protocol, student inclusion recommendations, mobility considerations, transfer considerations, toileting protocol, physical education recommendations, fieldtrip information, transportation considerations, evacuation plan, environmental and scholarly considerations, consent and authorization, and an annual renewal document.

CONCLUSION

Further research is recommended to pilot the plan, solicit ongoing feedback, implement and evaluate the plan into routine education and health care practices.

The vitamin D status in a Chinese osteogenesis imperfecta population and its correlation with bone metabolic markers and bone density

Objective

Studies on the baseline vitamin D levels in osteogenesis imperfecta (OI) patients before medication are scarce. This study assessed the vitamin D status of a population with OI at both the overall level and within different age groups. It correlated baseline 25-hydroxyvitamin D (25(OH)D) levels with other bone-related factors, biochemical markers, and bone density.

Patients and methods

We collected 25(OH)D levels from 95 OI patients in East China (59 under 18 years old and 36 over 18 years old). Postmenopausal women and men over 50 years old are excluded. Measurements included body indicators, biochemical markers, and bone mineral density (BMD) assessed by Dual-energy X-ray absorptiometry (DXA). Data analysis was performed using SPSS 26.0.

Results

In the overall population, among those under 18 years old, and among those over 18 years old, 87.4, 83.1, and 94.4%, respectively, were vitamin D deficient (<30 ng/mL), while 47.4, 40.7, and 58.3% had vitamin D deficiency (<20 ng/mL), respectively. In the overall population and among those under 18 years old, serum 25(OH)D levels were negatively correlated with age and parathyroid hormone (PTH) levels, and 25(OH)D levels (<10 ng/mL, 10-20 ng/mL, 20-30 ng/mL, >30 ng/mL) showed a negative correlation with BMI. In OI patients under 18 years old, serum 25(OH)D was negatively correlated with serum β-CTX levels. In adult male OI population, 25(OH)D levels were negatively correlated with OI severity (Type I, IV, III). No statistically significant correlation was found between 25(OH)D levels and BMD Z-scores.

Conclusion

This study on OI in East China reveals significant vitamin D insufficiency and deficiency in baseline levels among pediatric, adolescent and adult OI patients. It assesses the correlation of 25(OH)D levels with various influencing factors, providing crucial insights into understanding the impact of OI on vitamin D status across different age groups and aiding in better clinical management of OI patients.

Risk perception for fractures and its related factors among family caregivers of underage patients with osteogenesis imperfecta in China: A cross-sectional study

PURPOSE

To describe the level of risk perception for fractures among family caregivers of children diagnosed with osteogenesis imperfecta, and explore the related factors.

DESIGN AND METHODS

This was a cross-sectional survey study. A self-administered questionnaire on family caregivers' perception of fracture risk of underage patients with osteogenesis imperfecta was used. The study was performed in mainland China from May to December 2022, with 127 family caregivers of patients aged 3-17. Stepwise backwards multivariable linear regression analysis was undertaken to examine risk factors for caregivers' risk perception of fractures.

RESULTS

A total of 16.54% of caregivers had a higher level of risk perception for fractures of patients. The caregiver's educational level, the family members, the patient's self-care ability, fracture times in the past year, and whether or not they had received community services were associated with the caregiver's risk perception for fracture.

CONCLUSIONS

Patients with osteogenesis imperfecta will eventually leave the medical system and receive more support from themselves or family caregivers instead of health personnel. These findings should be incorporated into the prevention and health education of fractures in caregivers of underage patients with osteogenesis imperfecta to help develop effective risk communication strategies and induce caregivers to implement appropriate protective behaviors.

PRACTICE IMPLICATIONS

It is important to evaluate the risk perception for fractures and its related factors among family caregivers of underage patients with osteogenesis imperfecta. Identifying these factors can help healthcare providers to screen caregivers with high perceived level of fracture risk in a quicker and earlier way. This study provides evidence for the establishment of interventions to balance caregivers' risk perception and patient socialization.

Low muscle density in children with osteogenesis imperfecta using opportunistic low-dose chest CT: a case-control study

BACKGROUND

The aim of the study was to investigate the muscle differences in children with osteogenesis imperfecta (OI) using opportunistic low-dose chest CT and to compare different methods for the segmentation of muscle in children.

METHODS

This single center retrospective study enrolled children with OI and controls undergoing opportunistic low-dose chest CT obtained during the COVID pandemic. From the CT images, muscle size (cross-sectional area) and density (mean Hounsfield Units [HU]) of the trunk muscles were measured at the mid-T4 and the mid-T10 level using two methods, the fixed thresholds and the Gaussian mixture model. The Bland-Altman method was also used to compute the strength of agreement between two methods. Comparison of muscle results between OI and controls were analyzed with Student t tests.

RESULTS

20 children with OI (mean age, 9.1 ± 3.3 years, 15 males) and 40 age- and sex-matched controls were enrolled. Mean differences between two methods were good. Children with OI had lower T4 and T10 muscle density than controls measured by the fixed thresholds (41.2 HU vs. 48.0 HU, p < 0.01; 37.3 HU vs. 45.9 HU, p < 0.01). However, children with OI had lower T4 muscle size, T4 muscle density, T10 muscle size and T10 muscle density than controls measured by the Gaussian mixture model (110.9 vs. 127.2 cm2, p = 0.03; 44.6 HU vs. 51.3 HU, p < 0.01; 72.6 vs. 88.0 cm2, p = 0.01; 41.6 HU vs. 50.3 HU, p < 0.01, respectively).

CONCLUSIONS

Children with OI had lower trunk muscle density indicating that OI might also impair muscle quality. Moreover, the fixed thresholds may not be suitable for segmentation of muscle in children.

Safety and Efficacy of Denosumab in Children With Osteogenesis Imperfecta-the First Prospective Comparative Study

CONTEXT

Denosumab is a potential therapeutic agent for osteogenesis imperfecta (OI), but its efficacy and safety remain unclear in children with OI.

OBJECTIVE

We aimed to investigate the effects of denosumab on bone mineral density (BMD), spinal morphometry, and safety in children with OI compared with zoledronic acid.

METHODS

In this prospective study, 84 children or adolescents with OI were randomized to receive denosumab subcutaneous injection every 6 months or zoledronic acid intravenous infusion once. Changes of BMD and its Z-score, vertebral shape, serum levels of calcium and bone turnover biomarkers were assessed during the 1-year treatment.

RESULTS

After 12 months of treatment, BMD at the lumbar spine, femoral neck, and total hip significantly increased by 29.3%, 27.8%, and 30.2% in the denosumab group, and by 32.2%, 47.1%, and 41.1% in the zoledronic acid group (all P < .001 vs baseline). Vertebral height and projection area significantly increased after denosumab and zoledronic acid treatment. Rebound hypercalcemia was found to be a common and serious side effect of denosumab, of which 14.3% reached hypercalcemic crisis. Rebound hypercalcemia could be alleviated by switching to zoledronic acid treatment.

CONCLUSION

Treatment with denosumab or zoledronic acid is beneficial in increasing BMD and improving the spinal morphometry of children with OI. However, denosumab should be used with caution in pediatric patients with OI because of its common and dangerous side effect of rebound hypercalcemia. The appropriate dosage and dosing interval of denosumab need to be further explored in children with OI.

Prevalence, number of fractures, and hospital characteristics among the pediatric population with osteogenesis imperfecta: results from the nationwide registry of Türkiye

OBJECTIVE

Osteogenesis imperfecta is a rare connective tissue disorder with an estimated number of 4-20 cases per 100 000 inhabitants. Although the prevalence differs among regions, there are only a few number of national registry studies published previously. The aim of this study was to determine the prevalence of osteogenesis imperfecta among the pediatric age group in Türkiye, together with the patient and hospital characteristics.

METHODS

Via the e-health database of the Turkish Ministry of Health, we collected and retrospectively evaluated the medical records of the patients who were under 18 years of age with the diagnosis of osteogenesis imperfecta between 2016 and 2022. Total number of fractures, treatment modalities, and the hospital characteristics were also recorded. Two thousand seven hundred forty patients were extracted with a mean age of 9.77 ± 4.81 years.

RESULTS

The prevalence of osteogenesis imperfecta in Türkiye among the pediatric population was calculated as 11.6 per 100 000 individuals. The median annual incidence was 31.5 per 100 000 live births between 2016 and 2022. There were 17.4 hospital admissions per patient per year. The mean age at the time of in-hospital mortality was 4.08 ± 5.03 years. The fracture rate per patient per year was 0.56 and conservative treatment was the most commonly preferred modality for all ages.

CONCLUSION

This is the first registry-based nationwide study of osteogenesis imperfecta patients in Türkiye, providing important characteristics of the disease. Together with the help of the ongoing development of national health database systems, precision in patient identification would yield substantial benefits in terms of management of osteogenesis imperfecta.

Influence of zoledronic acid and pamidronate on tooth eruption in children with osteogenesis imperfecta

INTRODUCTION

Osteogenesis imperfecta (OI) is a congenital disease comprising a heterogeneous group of inherited connective tissue disorders. The main treatment in children is bisphosphonate therapy. Previous animal studies have shown that bisphosphonates delay tooth eruption. The aim of this study is to determine whether patients with OI treated with pamidronate and/or zoledronic acid have a delayed eruption age compared to a control group of healthy children.

METHODS

An ambispective longitudinal cohort study evaluating the age of eruption of the first stage mixed dentition in a group of children with OI (n = 37) all treated with intravenous bisphosphonates compared with a group of healthy children (n = 89). Within the study group, the correlation (Pearson correlation test) between the type of medication administered (pamidronate and/or zoledronic acid) and the chronology of tooth eruption is established, as well as the relationship between the amount of cumulative dose received and tooth eruption.

RESULTS

The age of eruption of the study group was significantly delayed compared to the age of eruption of the control group for molars and lateral incisors (p < 0.05). Patients who received higher cumulative doses had a delayed eruption age compared to those with lower cumulative doses (p < 0.05). There is a high positive correlation between age of delayed tooth eruption and Zoledronic acid administration.

CONCLUSION

Patients with OI have a delayed eruption of the 1st stage mixed dentition compared to a control group of healthy children. This delayed eruption is directly related to the cumulative dose of bisphosphonates and the administration of zoledronic ac.

Cranio-cervical abnormalities in moderate-to-severe osteogenesis imperfecta - Genotypic and phenotypic determinants

INTRODUCTION

Cranio-cervical anomalies are significant complications of osteogenesis imperfecta (OI), a rare bone fragility disorder that is usually caused by mutations in collagen type I encoding genes.

OBJECTIVE

To assess cranio-cervical anomalies and associated clinical findings in patients with moderate-to-severe OI using 3D cone beam computed tomography (CBCT) scans.

METHODS

Cross-sectional analysis of CBCT scans in 52 individuals with OI (age 10-37 years; 32 females) and 40 healthy controls (age 10-32 years; 26 females). Individuals with a diagnosis of OI type III (severe, n = 11), type IV (moderate, n = 33) and non-collagen OI (n = 8) were recruited through the Brittle Bone Disorders Consortium. Controls were recruited through the orthodontic clinic of the University of Missouri-Kansas City (UMKC).

RESULTS

OI and control groups were similar in mean age (OI: 18.4 [SD: 7.2] years, controls: 18.1 [SD: 6.3] years). The cranial base angle was increased in the OI group (OI: mean 148.6° [SD: 19.3], controls: mean 130.4° [SD: 5.7], P = .001), indicating a flatter cranial base. Protrusion of the odontoid process into the foramen magnum (n = 7, 14%) and abnormally located odontoid process (n = 19, 37%) were observed in the OI group but not in controls. Low stature, expressed as height z-score (P = .01), presence of DI (P = .04) and being male (P = .04) were strong predictors of platybasia, whereas height z-score (P = .049) alone was found as positive predictor for basilar impression as per the Chamberlain measurement.

CONCLUSION

The severity of the phenotype in OI, as expressed by the height z-score, correlates with the severity of cranial base anomalies such as platybasia and basilar impression in moderate-to-severe OI. Screening for cranial base anomalies is advisable in individuals with moderate-to-severe OI, with special regards to the individuals with a shorter stature and DI.

Reducing fracture incidence in children with osteogenesis imperfecta: contribution of orthotics to bisphosphonates treatment

PURPOSE

To determine whether there was a reduction in fracture incidence amongst children with OI who were treated with both bisphosphonates and orthoses.

OBJECTIVE

Was there an additional reduction in fracture incidence amongst children with Osteogenesis Imperfecta (OI) treated with both bisphosphonates and Hip-Knee-Ankle-Foot-Orthosis (HKAFO)?

MATERIALS AND METHODS

Of the 129 OI patients treated from 1990 to 2017, retrospective data from 48 patients who participated in the bisphosphonates-orthosis regime were analyzed including the incidence of fractures and modalities of fracture treatment.

RESULTS

Bisphosphonates usage was more frequent than bracing and there were more positive changes (smaller or equal number of fractures each year) than negative changes (more fractures each year); negative changes were scarce, explained by non-compliance with the use of bracing. Poisson regression models were significant for positive changes, whereas the interaction between them was borderline significant. The main finding is that the association between bisphosphonates usage and the number of positive changes was stronger among the patients who used braces more frequently and weaker among patients who used bracing less frequently.

CONCLUSIONS

Bracing of OI patients has an additive effect on bisphosphonate treatment in fracture prevention which should lead to the reconsideration of a hybrid approach to OI management.

An Analysis From a Tertiary Pediatric Hospital: Does Physical Activity Play a Role in the Management of Children and Young Adults With Osteogenesis Imperfecta?

INTRODUCTION

Osteogenesis imperfecta (OI) is a hereditary connective tissue disorder characterized by reduced bone density and increased proneness to fractures. It manifests across a varied clinical spectrum of expressions in children and young adults. It is crucial for children with OI to have a multidisciplinary follow-up, including orthopedics, pediatrics, and physical medicine and rehabilitation. Although exercise may have no effect on the disease itself, it might improve the autonomy, self-esteem, and fitness of these children.  Methods: Retrospective cohort analysis of children and young adults aged three or more years old followed-up in a Level III Pediatric Hospital between 1995 and 2020. Demographic and clinical data were obtained from the hospital records and from the caregivers via phone calls. To our knowledge, this is the first national case series published assessing exercise habits in children with this condition.

RESULTS

Among the 21 patients studied, the median age was 14 years, with no gender predominance. Eighteen (86%) practiced regular physical activity, while the remaining three (14%), all of whom were type III OI, were totally dependent. Of the aforementioned 18 children, 12 (67%) considered practicing the same level of physical activity compared to their healthy peers, although most of them needed adaptations. The most reported extracurricular activity was swimming, in 50% of the cases. About 39% engaged in physical activity two times or less per week, and 89% practiced for one hour or less per session.

DISCUSSION

Over the years, it has become clear that physical activity is an important part of OI management. While awareness of the importance of exercise already exists, proper planning, follow-up, and monitoring are essential.

Dysregulation of MicroRNAs in Adult Osteogenesis Imperfecta: The miROI Study

As epigenetic regulators of gene expression, circulating micro-RiboNucleic Acids (miRNAs) have been described in several bone diseases as potential prognostic markers. The aim of our study was to identify circulating miRNAs potentially associated with the severity of osteogenesis imperfecta (OI) in three steps. We have screened by RNA sequencing for the miRNAs that were differentially expressed in sera of a small group of OI patients versus controls and then conducted a validation phase by RT-qPCR analysis of sera of a larger patient population. In the first phase of miROI, we found 79 miRNAs that were significantly differentially expressed. We therefore selected 19 of them as the most relevant. In the second phase, we were able to validate the significant overexpression of 8 miRNAs in the larger OI group. Finally, we looked for a relationship between the level of variation of the validated miRNAs and the clinical characteristics of OI. We found a significant difference in the expression of two microRNAs in those patients with dentinogenesis imperfecta. After reviewing the literature, we found 6 of the 8 miRNAs already known to have a direct action on bone homeostasis. Furthermore, the use of a miRNA-gene interaction prediction model revealed a 100% probability of interaction between 2 of the 8 confirmed miRNAs and COL1A1 and/or COL1A2. This is the first study to establish the miRNA signature in OI, showing a significant modification of miRNA expression potentially involved in the regulation of genes involved in the physiopathology of OI. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Analysis of miRNAs in Osteogenesis imperfecta Caused by Mutations in COL1A1 and COL1A2: Insights into Molecular Mechanisms and Potential Therapeutic Targets

Osteogenesis imperfecta (OI) is a group of connective tissue disorders leading to abnormal bone formation, mainly due to mutations in genes encoding collagen type I (Col I). Osteogenesis is regulated by a number of molecules, including microRNAs (miRNAs), indicating their potential as targets for OI therapy. The goal of this study was to identify and analyze the expression profiles of miRNAs involved in bone extracellular matrix (ECM) regulation in patients diagnosed with OI type I caused by mutations in COL1A1 or COL1A2. Primary skin fibroblast cultures were used for DNA purification and sequence analysis, followed by analysis of miRNA expression. Sequencing analysis revealed mutations of the COL1A1 or COL1A2 genes in all OI patients, including four previously unreported. Amongst the 40 miRNAs analyzed, 9 were identified exclusively in OI cells and 26 in both OI patients and the controls. In the latter case, the expression of six miRNAs (hsa-miR-10b-5p, hsa-miR-19a-3p, hsa-miR-19b-3p, has-miR-204-5p, has-miR-216a-5p, and hsa-miR-449a) increased, while four (hsa-miR-129-5p, hsa-miR-199b-5p, hsa-miR-664a-5p, and hsa-miR-30a-5p) decreased significantly in OI cells in comparison to their expression in the control cells. The identified mutations and miRNA expression profiles shed light on the intricate processes governing bone formation and ECM regulation, paving the way for further research and potential therapeutic advancements in OI and other genetic diseases related to bone abnormality management.

NGS analysis of collagen type I genes in Polish patients with Osteogenesis imperfecta: a nationwide multicenter study

Osteogenesis imperfecta (OI) is a rare genetic disorder of the connective tissue. It presents with a wide spectrum of skeletal and extraskeletal features, and ranges in severity from mild to perinatal lethal. The disease is characterized by a heterogeneous genetic background, where approximately 85%-90% of cases have dominantly inherited heterozygous pathogenic variants located in the COL1A1 and COL1A2 genes. This paper presents the results of the first nationwide study, performed on a large cohort of 197 Polish OI patients. Variants were identified using a next-generation sequencing (NGS) custom gene panel and multiplex ligation probe amplification (MLPA) assay. The following OI types were observed: 1 (42%), 2 (3%), 3 (35%), and 4 (20%). Collagen type I pathogenic variants were reported in 108 families. Alterations were observed in α1 and α2 in 70% and 30% of cases, respectively. The presented paper reports 97 distinct causative variants and expands the OI database with 38 novel pathogenic changes. It also enabled the identification of the first glycine-to-tryptophan substitution in the COL1A1 gene and brought new insights into the clinical severity associated with variants localized in "lethal regions". Our results contribute to a better understanding of the clinical and genetic aspects of OI.

Standardized growth charts for children with osteogenesis imperfecta

BACKGROUND

Osteogenesis imperfecta (OI) is associated with short stature, which is mild, severe and moderate in OI types I, III and IV, respectively. Standardized OI type- and sex-specific growth charts across all pediatric ages do not exist.

METHODS

We assessed 573 individuals with OI (type I, III or IV), each with at least one height measurement between ages 3 months and 20 years (total 6523 observations). Analogous to the Centers for Disease Control pediatric growth charts, we generated OI type- and sex-specific growth charts for infants (ages 3-36 months) as well as children and adolescents (ages 2-20 years). Growth curves were fitted to the data using the LMS method and percentiles were smoothed.

RESULTS

Age was associated with a decline in height z-scores (p < 0.001 for all OI types), which was more pronounced in females. Height multiplier curves were produced to predict adult height in children with OI. Among individuals with OI type I, those with COL1A1 pathogenic variants leading to haploinsufficiency were taller than those with COL1A1 or COL1A2 pathogenic variants not leading to haploinsufficiency.

CONCLUSION

Our standardized OI type- and sex-specific growth charts can be used to assess the growth of individuals with OI from infancy to adulthood.

IMPACT

Standardized osteogenesis imperfecta (OI) type- and sex-specific growth charts across all pediatric ages do not exist. Our study is the first to generate OI type- and sex-specific growth charts across all pediatric ages. Our height multiplier curves can be utilized to predict adult height in children with OI.

The patient-related factors in revision procedures on tibia of patients with osteogenesis imperfecta treated with the Peter-Williams nail

OBJECTIVE

To investigate the patient-related factors that affect the revision rate for the tibia in patients with osteogenesis imperfecta treated with the Peter-Williams nail, and to explore the relationship between the risk factors and complications postsurgery.

METHODS

We retrospectively analysed the data of 211 patients (93 females (44.08%) and 118 males (55.92%)) with osteogenesis imperfecta treated with Peter-Williams. The factors affecting surgical revision were analysed by performing binary logistic regression. Then, a total of 211 patients with type III, type I or type IV OI were divided into five groups according to the results of regression. Statistical comparison of these groups was performed to further investigate the relationship between patient-related factors and revision procedures. Statistical comparison was also performed to analyse the relationship between the classification and postoperative complications.

RESULTS

Among the 211 patients who underwent surgery, 40 had type I OI, 109 had type IV OI, and 62 had type III OI. Binary logistic regression revealed that the classification (OR = 3.32, 95% CI 1.06-10.39, P = 0.039) and initial operation age (OR = 0.83, 95% CI 0.76-0.92, P < 0.001) were significantly correlated with revision procedures. In type III patients, the initial operation age was significantly correlated with revision procedures (P < 0.001), and the revision rate was lower in patients aged 9 to12 years (P = 0.001). In type I and IV patients, the initial operation age was not significantly correlated with revision procedures (P = 0.281). Classification had a significant effect on postoperative deformity (P = 0.003).

CONCLUSIONS

The study reported that the age of initial surgery and classification were the influencing factors affecting the revision procedures of tibia in patients with osteogenesis imperfecta treated with the Peter-Williams nail. In patients with type III disease, the revision rate was lower individuals aged 9-12 years old, and a higher incidence of postoperative deformity was observed.

Impact of caregiver's eHealth literacy, financial well-being, and mental health on quality of life of pediatric patients with osteogenesis imperfecta

OBJECTIVE

This study assesses the association between health-related quality of life (HRQoL) for pediatric patients with osteogenesis imperfecta (OI) and their caregivers' eHealth literacy (eHL), financial well-being, and mental health along with the impact of eHealth literacy on the financial well-being and mental health of OI caregivers.

METHODS

Participants were recruited from a member pool of two OI patient organizations in China. Information about patients' HRQoL and their caregivers' eHL, financial well-being, and mental health was collected. Structure equation modeling (SEM) was used to estimate the relationship between the measures. The robust weighted least square mean and variance adjusted estimator was used. Three criteria, the comparative fit index, the Tucker-Lewis index, and the root mean square error of approximation, were used to evaluate the goodness-of-fit of the model.

RESULTS

A total of 166 caregivers completed the questionnaires. Around 28.3% indicated that pediatric OI patients experienced problems related to mobility, and 25.3% reported difficulty doing usual activities. Around 52.4% of caregivers reported that their care receivers have some emotional problems while 8.4% reported that their care receivers have "a lot of" emotional problems. 'Some problems' on all dimensions on EQ-5D-Y was the most frequently reported health state (13.9%), and around 10.0% have no problems on all dimensions on EQ-5D-Y. Caregivers tended to show a significantly high eHL, financial well-being, and mental health when their care receivers reported no problems with usual activities and emotions. The SEM demonstrated a significant and positive relationship between eHL, financial well-being, and mental health.

CONCLUSION

OI caregivers with high eHL reported satisfactory financial well-being and mental health; their care receivers rarely reported living with poor HRQoL. Providing multicomponent and easy-to-learn training to improve caregivers' eHL should be highly encouraged.

Delivering a Home-Based Exercise Program to Youth With Osteogenesis Imperfecta: Protocol for a Comparative-Approach Study

BACKGROUND

Osteogenesis imperfecta (OI) is a rare bone fragility disorder associated with muscle weakness. Individuals with OI may therefore benefit from exercise interventions aiming to improve muscle and bone strength. Given the rarity of OI, many patients do not have access to exercise specialists who are familiar with the disorder. As such, telemedicine, the provision of health care through technology to provide care at a distance, may be well suited for this population.

OBJECTIVE

The main objectives are (1) to investigate the feasibility and cost-effectiveness of 2 telemedicine approaches for the delivery of an exercise intervention for youth with OI and (2) to assess the impact of the exercise intervention on muscle function and cardiopulmonary fitness in youth with OI.

METHODS

Patients with OI type I (the mildest form of OI; n=12, aged 12-16 years) from a pediatric orthopedic tertiary hospital will be randomized to receive a 12-week remote exercise intervention in either (1) a supervised group (n=6), monitored every session, or (2) a follow-up group (n=6), receiving monthly progress update appointments. Participants will undergo the following pre- and postintervention evaluations: sit-to-stand test, push-up test, sit-up test, single-legged balance test, and a heel-rise test. Both groups will be given the same 12-week exercise regimen, which includes cardiovascular, resistance, and flexibility training. For each exercise training session involving the supervised group, a kinesiologist will provide instructions to participants through live video sessions using a teleconferencing application. On the other hand, the follow-up group will discuss their progress with the kinesiologist every 4 weeks over a teleconferencing video call. Feasibility will be assessed by recruitment, adherence, and completion rates. A cost-effectiveness analysis of both approaches will be computed. Changes in muscle function and cardiopulmonary fitness will be examined between the 2 groups, pre- and postintervention.

RESULTS

It is anticipated that the supervised group will have higher adherence and completion rates compared to the follow-up group, which may be associated with greater physiological benefits; however, it may not be as cost-effective compared to the follow-up approach.

CONCLUSIONS

By determining the most feasible telemedicine approach, this study may serve as a basis for providing increased access to specialized adjunct therapies for individuals with rare disorders.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/40262.

The Design, Development, and Usability Testing of an eHealth Program for Youths With Osteogenesis Imperfecta: Protocol for a 2-Phase User-Centered Mixed Methods Study

BACKGROUND

Innovative approaches are needed to address the self-management needs of youths with osteogenesis imperfecta (OI) transitioning into adult-oriented health care systems. Using a sequentially phased research approach, the goal is to design, develop, and test the usability of an innovative eHealth program called "Teens Taking Charge: Managing OI Online," hereafter named "Teens OI." This program seeks to optimize self-management, facilitate a successful transition to adult care, and address a critical gap in the quality of care for youths with OI.

OBJECTIVE

The study objectives are to (1) design and develop an English and French version of the Teens OI and (2) test the usability of the Teens OI in terms of efficiency, effectiveness, and satisfaction from the perspectives of youths with OI and their parents.

METHODS

A user-centered design is presently in progress to design and develop Teens OI. A "Website Design and Development Council" (ie, Council) has been convened, with 20 youths and parent dyads recruited and global experts surveyed at an international meeting. With unanimous support from the Council, usability testing of the Teens OI will ensue in 4 iterative cycles with 32 youth-parent dyads. All sociodemographic and usability metrics will be descriptively analyzed. All recorded interview and focus group data are analyzed using content analysis techniques involving an iterative process of data reduction, data display, conclusion drawing, and verification.

RESULTS

As of December 2022, an 8-person, interdisciplinary Teens OI council, comprising 4 health care professionals, 3 youths and young adults with OI, and 1 parent, has been convened to oversee the design and development of Teens OI. Two cycles of interviews have been conducted with 10 youths with OI with or without their parents (n=6) from December 2021 to September 2022. Data analysis has been in progress since April 2022. Aim 2 is ethically approved and will commence following the completion of content development, expected by late July 2023. Preliminary analysis indicates that the following topics need to be prioritized for the youths: mental health, pain, accessibility, medical care, education, community, and parental care.

CONCLUSIONS

The proposed study will design and develop a self-management and transitional care program for youths with OI in partnership with patients, caregivers, and health care professionals. This study leverages youths' openness to adopt eHealth technologies to meet their needs and has the potential to actively engage them to autonomously manage their lifelong conditions, and facilitate a successful transition to adult health care. Finally, the proposed study will also address a critical gap in the quality of care and the growing concern that the OI population transitioning from pediatric to adult care is at risk of various adverse events associated with the transition.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/47524.

Surgical outcomes for spinal deformity in osteogenesis imperfecta

STUDY DESIGN

IRB approved retrospective review of the the SHOnet (Shriners Health Outcomes Network).

OBJECTIVES

Osteogenesis imperfecta (OI) is the most prevalent genetic disorder of bone and connective tissue in the pediatric population, with an incidence of 1/15,000-20,000. Scoliosis has been reported to be present in 39-100% of OI patients and may continue to progress into adulthood but there is little information on the perioperative outcomes, rates of revision surgery and complications in this fragile population. The purpose of this study is to examine the prevalence of scoliosis in the OI population across a tertiary care multihospital system. The rate at which these patients progress to surgery, the perioperative complication rate and if there is an association between complications and age at surgical intervention, pre-operative Cobb angle, number of fractures, and type of OI. Incidence of scoliosis in OI may be lower than previously reported, many may never require surgical intervention and those that do require surgical intervention have an 8% reoperation rate at an average of 3.3 years postop.

METHODS

IRB approved retrospective review of the the SHOnet (Shriners Health Outcomes Network), electronic health record data warehouse from January 1, 2011 and December 31, 2017. Inclusion criteria included International Classification of Diseases (ICD) code for osteogenesis imperfecta and scoliosis. The data warehouse was queried for age, gender, presence of vertebral body fractures, proximal junctional kyphosis, basilar invagination, bisphosphonate use, and perioperative complications including postoperative infection.

RESULTS

There were 2372 patients with osteogenesis imperfecta, 429 or 18.1% also had a diagnosis of scoliosis, while 81.9% did not (see Table 1). Only 74 patients (17.2%) of the patients that had scoliosis underwent spine surgery, 12 of which had staged surgery with an average preop thoracic Cobb 58.18 (range 7-115), and thoracolumbar Cobb 59.83 (range 5-145). Six patients (8%) required revision spine surgery. Average time to revision was 3.88 years (6.9-69mo). Bisphosphonate use was present in 35.5% of patients that did not require surgery and in 40.5% that did.

CONCLUSION

With over 2300 patients, this is the largest study to date on scoliosis in patients with OI. We found that contrary to prior studies which had indicated the incidence of scoliosis ranges from 39 to 100% that it was only present in 18% of our patients. This indicates that the incidence of scoliosis in OI is potentially lower than previously reported, though due to the nature of this study it may be underreported. Furthermore, only 17% of those patients in our study with scoliosis eventually underwent surgery. It is important to note that many patients treated non-operatively had deformity within the operative range, which may indicate that they were not considered good candidates for surgical intervention. Lastly, we found that bisphosphonate use did not appear to affect the likelihood of progression to surgery in this group of patients, though this may be due to later initiation of the bisphosphonate use.

Multimodal Pain Management of Children Diagnosed with Osteogenesis Imperfecta: An Integrative Literature Review

OBJECTIVES

The objective of this literature review was to evaluate multimodal therapies and interventions that help prevent progression and manage pain in children with OI.

DESIGN

A systematic review of literature utilizing PRISMA guidelines.

DATA SOURCES

The Cumulative Index to Nursing and Allied Health Literature (CINAHL) Complete, PubMed, PsycINFO, UpToDate, and ProQuest Nursing & Allied Health Source.

REVIEW/ANALYSIS METHODS

Existing literature on pain management in pediatric patients diagnosed with OI was reviewed and appraised. Fifteen studies met the criteria for review.

RESULTS

Results indicated that therapies addressing pain management are most effective when they use a multimodal approach that promotes bone strength, psychological support, reduces the risk of fractures, increases bone stability, and maintains physiological function. Four multimodal treatments for pain management in children with OI were identified including bisphosphonate therapy, surgical intervention, physical therapy, and psychosocial support.

CONCLUSIONS

Developing a finite understanding of the utilization of multimodal therapies to manage and treat pain can assist in engineering treatments that improve the quality of life for children diagnosed with OI.

Type XV osteogenesis imperfecta: A novel mutation in the WNT1 gene, c.620G >A (p.R207H), is associated with an inner ear deformity

The Wnt signaling pathway is vital in encouraging bone growth. WNT1 gene mutations have been identified as the major cause of type XV osteogenesis imperfecta (OI). Described here is a case of complex heterozygous WNT1 c.620G>A (p.R207H) and c.677C >T (p.S226L) OI caused by a novel mutation at locus c.620G >A (p.R207H). The female patient had type XV OI, distinguished by poor bone density, frequent fractures, a small stature, skull softening, lack of dentine hypoplasia, a brain malformation, and obvious blue sclera. A CT scan of the temporal bone revealed abnormalities of the inner ear, necessitating a hearing aid 8 months after birth. There was no family history of such disorders in the proband's parents. The proband inherited complex heterozygous WNT1 gene variants c.677C>T (p.S226L) and c.620G>A (p.R207H) from her father and mother, respectively. Presented here is a case of OI with inner ear deformation caused by c.620G>A (p.R207H), which is a novel WNT1 site mutation. This case broadens the genetic spectrum of OI and it provides a rationale for genetic testing of mothers and a medical consultation to estimate the risk of fetal illness.

Osteoporosis in children and adolescents: how to treat and monitor?

Osteoporosis is a condition of increased bone fragility associated with fractures. Apart from primary genetic osteoporotic conditions, secondary osteoporosis in children is being increasingly recognized. As a result, there is growing interest in its prevention and treatment. Important goals of care are to prevent fractures, increase bone mass and trabecular and cortical thickness, reshape vertebral fractures, prevent (or correct) skeletal deformities, and improve mobility, independence, and quality of life. Secondary pediatric osteoporosis is often of multifactorial origin since affected children frequently have more than one acquired factor that is detrimental to bone health. Typical conditions causing osteoporosis are leukemias, progressive muscle or neurological disorders, as well as chronic inflammatory conditions and their treatment. Management of children with osteoporosis involves a multidisciplinary team involving pediatric experts from different subspecialties. With regard to prevention and early intervention, it is important to provide optimal management of any underlying systemic conditions including avoidance, or dose-reduction, of osteotoxic medications. Basic supporting life-style measures, such as appropriate nutrition, including adequate calcium intake and vitamin D, and physical activity are recommended, where possible. When pediatric treatment criteria for osteoporosis are met, antiresorptive drugs constitute the first pharmacological line treatment.

CONCLUSION

This clinical review focuses on the prevention, treatment, and follow-up of children with, or at risk of developing, osteoporosis and the transition from pediatric to adult care.

WHAT IS KNOWN

• Osteoporosis and associated fractures can cause significant morbidity and reduce the quality of life. • The developing skeleton has huge potential for recovery and reshaping, thus early detection of fractures, assessment of recovery potential, and treatment of children with osteoporosis can prevent future fractures, deformities, and scoliosis, improve function and mobility, and reduce pain.

WHAT IS NEW

• Osteoporosis in children and adolescents requires a multidisciplinary approach with a thorough assessment of recovery potential, and indication for therapy should be personalized. • Although bisphosphonates still represent the drug most commonly used to increase bone mass, improve mobility, and reduce pain and recurrence of fractures, new agents are being developed and could be beneficial in children with specific conditions.

COL1A2 (p.Gly322Ser) Mutation Causes Late-Onset Osteogenesis Imperfecta: A Case Report

Osteogenesis imperfecta (OI) is a genetically inherited disorder that mainly affects the bones and causes a generalized decrease in bone mass. OI has a broad clinical spectrum ranging from the most severe form of OI which may cause in-utero death or stillbirth to the milder form. Clinical manifestations normally mitigate with an increase in age. We report a case of a healthy 12-year-old male who presented with a spontaneous fracture of the femur without trauma. The patient has no previous history of fractures, bone deformities or systemic conditions. The initial physical examination was unremarkable except for a bilateral subtle grayish sclera. Calcium, phosphorus, vitamin D, blood urea nitrogen (BUN), creatinine, and parathyroid hormone (PTH) values were within normal range. After genetic testing, the patient was diagnosed with OI due to a pathogenic COL1A2 (c.964G>A [p.Gly322Ser]) mutation. The first manifestation was at 12 years of age with a femur spontaneous fracture, which brings to the fact that the patient has a late onset of OI.

Osteoporosis in children and young adults

Osteoporosis is a major public health problem with serious long-term complications. In children, the definition of osteoporosis is not only based on densitometric criteria but also takes into account vertebral and long bone fragility fractures. Several factors, such as long-term high-dose steroids, chronic inflammation, malnutrition, immobility, lack of sex steroids, and medication can reduce bone density and increase the risk for fragility fractures when left untreated. Also, genetic conditions can predispose to primary bone fragility disorders, with osteogenesis imperfecta being the most common. Furthermore, since the growing skeleton is at an increased rate of bone remodeling, the ability to heal long bone fractures and reshape vertebral fractures differentiates children from adults. The scope of this chapter is to review the risk factors of osteoporosis and fragility fractures and describe the commonest causes of primary and secondary osteoporosis and their management in children and young adults.

The moral experiences of children with osteogenesis imperfecta

BACKGROUND

Serious ethical problems have been anecdotally identified in the care of children with osteogenesis imperfecta (OI), which may negatively impact their moral experiences, defined as their sense of fulfillment towards personal values and beliefs.

RESEARCH AIMS

To explore children's actual and desired participation in discussions, decisions, and actions in an OI hospital setting and their community using art-making to facilitate their self-expression.

RESEARCH DESIGN

A focused ethnography was conducted using the moral experiences framework with data from key informant interviews; participant observations, semi-structured interviews, and practice-based research (art-making) with 10 children with OI; and local documents.

PARTICIPANTS AND RESEARCH CONTEXT

The study was conducted at a pediatric, orthopedic hospital.

ETHICAL CONSIDERATIONS

This study was approved by McGill University Institutional Review Board.

FINDINGS/RESULTS

Children expressed desires to participate in their care, but sometimes lacked the necessary resources and encouragement from healthcare providers. Art-making facilitated children's voice and participation in health-related discussions.

CONCLUSIONS

Healthcare providers are recommended to consider the benefits of art-making and educational resources to reduce discrepancies between children's actual and desired participation in care and promote positive moral experiences.

Clinical, genetic characteristics and treatment outcomes of children and adolescents with osteogenesis imperfecta: a two-center experience

BACKGROUND

Osteogenesis imperfecta (OI), is a heritable, heterogeneous connective tissue disorder, characterized by fragile bones. There are conflicting results about genotype-phenotype correlations and efficiency of bisphosphonate treatment in this disorder.

AIM

We aimed to evaluate the clinical, genetic characteristics, and long-term follow-up results of children and adolescents with OI.

MATERIALS AND METHODS

A two-center retrospective study was conducted using demographic, clinical, and genetic data obtained from the medical records of the patients.

RESULTS

Twenty-nine patients (62% male, median age; 3.6 years) with OI diagnosis from 26 families were included in the study. Thirteen different variants (nine were novel) were described in 16 patients in COL1A1, COL1A2, and P3H1 genes. Our siblings with homozygous P3H1 variants had a severe phenotype with intrauterine and neonatal fractures. Twenty-two patients were treated with bisphosphonates (17 of them with pamidronate, five with alendronate) with a median duration of 3.0 (1.6-4.8) years. Eleven patients (50%) suffered from fractures after the treatment. Haploinsufficiency variants in COL1A1 caused a milder skeletal phenotype with less fracture count and better treatment outcomes than structural variants. When compared with the anthropometric measurements at the initial diagnosis time, height Z-scores were lower on the last clinical follow-up (p = 0.009).

CONCLUSIONS

We could not find an obvious genotype-phenotype correlation in Turkish OI patients with COL1A1 or COL1A2 variants. Treatment with pamidronate was effective in reducing fracture counts, without any long-term adverse effects.

Pubertal growth in osteogenesis imperfecta caused by pathogenic variants in COL1A1/COL1A2

PURPOSE

Short stature is common in osteogenesis imperfecta (OI) and is usually severe in OI types III and IV. The characteristics of pubertal growth in OI have not been studied in detail.

METHODS

We assessed 82 individuals with OI caused by pathogenic variants in COL1A1 or COL1A2 who had annual height data between 6 and 16 years of age at a minimum. Height velocity curves were fitted to each individual's height data to describe the pubertal growth spurt.

RESULTS

Curve fitting was successful in 30 of the 33 individuals with OI type I (91%), in 23 of the 32 individuals with OI type IV (72%), and in 4 of the 17 participants with OI type III (24%). Pubertal growth spurt could be identified in most individuals with OI types I and IV, but rarely in OI type III. The timing of the pubertal growth spurt was similar between OI types I and IV in both sexes. However, height velocity was consistently higher in OI type I, leading to a widening height gap between OI types I and IV.

CONCLUSION

A pubertal growth spurt was present in most individuals with OI types I and IV, but rarely in OI type III.

Evaluation of growth, puberty, osteoporosis, and the response to long-term bisphosphonate therapy in four patients with osteoporosis-pseudoglioma syndrome

Osteoporosis-pseudoglioma syndrome (OPPG; MIM #259770) is a rare autosomal recessively inherited disease, characterized by early-onset osteoporosis and congenital blindness, caused by loss-of-function mutations in the LRP5 gene. Beneficial effects of bisphosphonate treatment in patients with OPPG are well known, while follow-up data on growth and pubertal parameters are limited. This article provides clinical follow-up data and long-term bisphosphonate treatment results in four OPPG patients from three unrelated families, ranging between 2.5 and 7 years of age at presentation. Clinical diagnosis was molecularly confirmed in all patients, with four different germline biallelic LRP5 mutations including a novel nonsense variant c.3517C>T (p.(Gln1173*)) in two siblings with marked phenotypic variability. Anthropometric and pubertal data and bone mineral density (BMD) measurements were evaluated retrospectively. Early puberty was observed in two patients. The bisphosphonate treatment duration of patients varied around 4-7 years and improvement in BMD z-scores with bisphosphonate treatment was demonstrated in all patients (z-score changes were +5.6, +4.0, +1.0, and +1.3). Although further research is needed to identify the possible association between early puberty and OPPG, all OPPG patients should be followed up with detailed endocrinological evaluation regarding pubertal status.

A single-centre study of genetic mutations, audiology, echocardiogram and pulmonary function in Saudi children with osteogenesis imperfecta

OBJECTIVES

Osteogenesis imperfecta (OI) is a heterogeneous group of inherited connective tissue disorders, characterised by skeletal fragility. Patients with OI may also exhibit extra-skeletal features like blue or grey scleral colour, fragile skin, easy bruising, joint laxity, short stature, deafness, cardiac valve abnormalities and abnormal pulmonary function. The objective of this study is to describe genetic mutations, prevalence of hearing issues, cardiac complications and impaired pulmonary function in children with OI.

METHODS

This is a cross-sectional study of 23 Saudi children aged 6 months to 18 years who were diagnosed with OI. The revised Sillence classification (2,105) was used to classify the OI type. Whole exome sequencing was performed for genetic mutations. The hearing was assessed by either pure-tone audiometry and/or otoacoustic emission testing. Cardiac defects were screened by echocardiograms. Spirometry was performed to assess pulmonary function. Data were analysed with descriptive statistics.

RESULTS

Based on the Sillence classification, 16 patients had OI type III, 6 had type IV and 1 had type I. Of the18 patients who had genetic sequencing, 66.6% had autosomal dominant and 33.3% had autosomal recessive mutations. Among children who had screening, hearing loss was diagnosed in 53% (9/17), congenital cardiac malformations in 26% (5/19) and restrictive lung disease in 70% (7/10).

CONCLUSIONS

We found significant extra-skeletal features and a high yield of genetic mutations associated with OI. We suggest further studies to develop a screening protocol for extra-skeletal features in children with OI.

Pamidronate Therapy Increases Trabecular Bone Complexity of Mandibular Condyles in Individuals with Osteogenesis Imperfecta

Patients with Osteogenesis Imperfecta (OI) present extra-skeletal manifestations, including important orodental and craniofacial features as dentinogenesis imperfecta, dental agenesis, failure of maxilla growth and hypotonia of masticatory muscles. These features may compromise vital functions speech and mastication. Studies have demonstrated that cyclic pamidronate infusion, the standard therapy for patients with moderate to severe OI, influences the histomorphometric pattern of different body bones. The present study aimed to investigate the condyle trabecular bone pattern in OI patients. We used fractal dimension (FD) analysis on dental panoramic radiographic images to characterize the mandibular condyle trabecular bone in adolescents diagnosed with OI and treated with pamidronate. Imaging exam of 33 adolescents of both sexes, aged between 12 and 17 years, were analyzed and compared with 99 age- and sex-matched healthy adolescents. FD in patients was significantly lower (1.23 ± 0.15) than in healthy controls (1.29 ± 0.11; p < 0.01). Type of OI, age at treatment onset, and the duration of therapy were variables that showed a statistically significant effect on the FD results. This study demonstrated that the bone architecture of mandibular condyles may be altered in pediatric patients with moderate and severe forms of OI. Also, pamidronate treatment seems to have a positive effect on condyle trabecular bone in these patients. This is supported by our finding that FD values were positively influenced by the length of cyclic pamidronate treatment at the time of imaging, as well as by the age of the individual at treatment onset.

Characterization and functional analysis of the adipose tissue-derived stromal vascular fraction of pediatric patients with osteogenesis imperfecta

Pediatric patients with Osteogenesis Imperfecta (OI), a heritable connective tissue disorder, frequently suffer from long bone deformations. Surgical correction often results in bone non-unions, necessitating revision surgery with autogenous bone grafting using bone-marrow-derived stem cells (BM-SC) to regenerate bone. BM-SC harvest is generally invasive and limited in supply; thus, adipose tissue's stromal vascular fraction (SVF) has been introduced as an alternative stem cell reservoir. To elucidate if OI patients' surgical site dissected adipose tissue could be used as autologous bone graft in future, we investigated whether the underlying genetic condition alters SVF's cell populations and in vitro differentiation capacity. After optimizing SVF isolation, we demonstrate successful isolation of SVF of pediatric OI patients and non-OI controls. The number of viable cells was comparable between OI and controls, with about 450,000 per gram tissue. Age, sex, type of OI, disease-causing collagen mutation, or anatomical site of harvest did not affect cell outcome. Further, SVF-containing cell populations were similar between OI and controls, and all isolated SVF's demonstrated chondrogenic, adipogenic, and osteogenic differentiation capacity in vitro. These results indicate that SVF from pediatric OI patients could be used as a source of stem cells for autologous stem cell therapy in OI.

Case report: Early-onset osteoporosis in a patient carrying a novel heterozygous variant of the WNT1 gene

The WNT1 gene is crucial for bone development and homeostasis. Homozygous mutations in WNT1 cause severe bone fragility known as osteogenesis imperfecta type XV. Moreover, heterozygous WNT1 mutations have been found in adults with early-onset osteoporosis. We identified a 35 year-old Caucasian woman who experienced multiple vertebral fractures two months after her second pregnancy. There was no history of risk factors for secondary osteoporosis or family history of osteoporosis. Dual-energy X-ray absorptiometry confirmed a marked reduction of bone mineral density (BMD) at the lumbar spine (0.734 g/cm², Z-score -2.8), femoral neck (0.48 g/cm², Z-score -3.5), and total hip (0.589 g/cm², Z-score -3.0). Blood tests excluded secondary causes of bone fragility. Genetic analysis revealed a heterozygous missense mutation (p.Leu370Val) in the WNT1 gene. Varsome classified it as a variant of uncertain significance. However, the fact that the Leucine residue at position 370 is highly conserved among vertebrate species and the variant has a very low allelic frequency in the general population would exclude the possibility of a polymorphism. The patient was treated for two years with teriparatide therapy associated with calcium and vitamin D supplements. During the follow-up period she did not report further clinical fractures. After 24 months of teriparatide, BMD increased at lumbar spine (+14.6%), femoral neck (+8.3%) and total hip (+4.9%) compared to baseline. We confirm that the heterozygous WNT1 mutation could cause a variable bone fragility and low turnover osteoporosis. We suggest that teriparatide is one of the most appropriate available therapies for this case.

Osteoporotic Fractures and Vertebral Body Reshaping in Children With Glucocorticoid-treated Rheumatic Disorders

CONTEXT

Osteoporotic fractures are an important cause of morbidity in children with glucocorticoid-treated rheumatic disorders.

OBJECTIVE

This work aims to evaluate the incidence and predictors of osteoporotic fractures and potential for recovery over six years following glucocorticoid (GC) initiation in children with rheumatic disorders.

METHODS

Children with GC-treated rheumatic disorders were evaluated through a prospective inception cohort study led by the Canadian STeroid-induced Osteoporosis in the Pediatric Population (STOPP) Consortium. Clinical outcomes included lumbar spine bone mineral density (LS BMD), vertebral fractures (VF), non-VF, and vertebral body reshaping.

RESULTS

A total of 136 children with GC-treated rheumatic disorders were enrolled (mean age 9.9 years, SD 4.4). The 6-year cumulative fracture incidence was 16.3% for VF, and 10.1% for non-VF. GC exposure was highest in the first 6 months, and 24 of 38 VF (63%) occurred in the first 2 years. Following VF, 16 of 19 children (84%) had complete vertebral body reshaping. Increases in disease activity and body mass index z scores in the first year and declines in LS BMD z scores in the first 6 months predicted incident VF over the 6 years, while higher average daily GC doses predicted both incident VF and non-VF. LS BMD z scores were lowest at 6 months (mean -0.9, SD 1.2) and remained low by 6 years even when adjusted for height z scores (-0.6, SD 0.9).

CONCLUSION

VF occurred early and were more common than non-VF in children with GC-treated rheumatic disorders. Eighty-four percent of children with VF underwent complete vertebral body reshaping, whereas vertebral deformity persisted in the remainder of children. On average, LS BMD z scores remained low at 6 years, consistent with incomplete recovery.

Long-term vascular access for infants with moderate to severe osteogenesis imperfecta

PURPOSE

Osteogenesis imperfecta (OI) is a genetic disorder that causes skeletal fragility. For the most fragile infants and young children with OI, intravenous (IV) bisphosphonate administration is essential, but IV access attempts often cause fractures. Port-a-caths help prevent these events, but some surgeons are hesitant to insert these devices in these infants due to lack of data on their safety.

METHODS

Retrospective study of pediatric patients with OI who underwent port-a-cath placement from 1999 to 2018; incidence of complications such as infection and thrombosis and need for reoperation or replacement are described.

RESULTS

Port-a-caths were placed in 17 patients with OI (median age, 8 mos [5-23 mos]; median weight, 5.8 kg [3.96-9.08 kg]) and remained in place for a median of 53.5 mos (10-127 mos). One port-a-cath was replaced because of thrombosis. Two port-a-caths were removed because of malfunction, one for skin erosion, and one for infection. In these five cases, replacement was not needed because patients could safely tolerate IV access. Two patients have their port-a-cath in place and the remaining ten patients had theirs removed electively as it was no longer needed.

CONCLUSION

Port-a-cath placement in pediatric patients with OI is safe and efficacious for durable central access, enabling reliable IV bisphosphonate delivery and reducing iatrogenic trauma.

Role of rs193922155 in the etiopathogenesis of osteogenesis imperfecta with description of the phenotype: A case report

INTRODUCTION

Osteogenesis imperfecta (OI) is a disorder of the connective tissue that mainly causes the bones to become excessively brittle. The vast majority of OI cases are associated with mutations in the genes encoding the I alpha.

PATIENT CONCERNS

A 57-year-old woman office worker was admitted because of severe, long-lasting pain in the thoracic spine while bending down. She and her daughter have a history of multiple atraumatic fractures form early childhood.

DIAGNOSIS

Both women were pre-diagnosed with OI based on their phenotype. The genetic testing has shown single nucleotide polymorphism (rs193922155) in the gene encoding the collagen type I alpha 1 which until now was only likely pathogenic.

INTERVENTIONS

Bone mineral density measurement revealed osteoporosis. The mother was prescribed with Vitamin D3 and calcium supplementation, but the daughter does not take any medication. The mother had vertebroplasty performed because of Th 9-12 vertebral body compression fractures. The cardiovascular diseases, spontaneous hematomas, joint dislocations were excluded.

OUTCOMES

For mother postoperative pain reduction was achieved.

CONCLUSION

To the best of our knowledge, this is the first publication that confirms the pathogenic effect of this mutation and describes the phenotype.

Experiences of Children With Osteogenesis Imperfecta in the Co-design of the Interactive Assessment and Communication Tool Sisom OI: Secondary Analysis of Qualitative Design Sessions

BACKGROUND

Children with osteogenesis imperfecta (OI) experience a diversity of symptoms that expose them to difficult physical, mental, and social challenges. Sisom (DHealth) is an interactive assessment and communication tool designed to help children aged 6-12 years with chronic conditions express their symptoms. Recently, the co-design of the Sisom OI paper prototype was launched by seeking the perspectives of end users, including children with OI and their clinicians.

OBJECTIVE

The aim of this study is to describe the experiences that children with OI were prompted to share with researchers during the co-design of the Sisom OI paper prototype.

METHODS

A secondary analysis of qualitative data was conducted at a university-affiliated, pediatric, orthopedic hospital. The data sources consisted of interview transcripts, drawings, field notes, and observations derived from interviewing 12 children with OI who participated in the co-design of the Sisom OI paper prototype. The themes and subthemes identified from the data sources were generated using qualitative description.

RESULTS

Three themes were identified. The first, Relating to Others, described the balance between feeling different versus feeling similar to other children. The subthemes were Common OI Experience, Feeling Different, and Feeling Just Like Others. The second, Relating to Their Condition, described children's positive and negative interactions with their own condition and health care. The subthemes were Understanding Their Condition, Special Relationship with the Hospital, and Difficult Treatments and Procedures. The third, Reflecting on Capabilities, described children's recognition of their strengths and limitations. The subthemes were Perceiving Limitations, Overcoming Isolation, and Celebrating Strengths.

CONCLUSIONS

This co-design process provided children with OI the space to not only contribute to the development of the end product but also eloquently describe their experiences. These findings, based on the descriptions given by the children themselves, offer us a unique understanding of what it means to grow up with OI.

Novel Mutations Within Collagen Alpha1(I) and Alpha2(I) Ligand-Binding Sites, Broadening the Spectrum of Osteogenesis Imperfecta - Current Insights Into Collagen Type I Lethal Regions

Osteogenesis imperfecta (OI) is a rare genetic disorder demonstrating considerable phenotypic and genetic heterogeneity. The extensively studied genotype-phenotype correlation is a crucial issue for a reliable counseling, as the disease is recognized at increasingly earlier stages of life, including prenatal period. Based on population studies, clusters in COL1A1 and COL1A2 genes associated with the presence of glycine substitutions leading to fatal outcome have been distinguished and named as "lethal regions." Their localization corresponds to the ligand-binding sites responsible for extracellular interactions of collagen molecules, which could explain high mortality associated with mutations mapping to these regions. Although a number of non-lethal cases have been identified from the variants located in lethal clusters, the mortality rate of mutations has not been updated. An next generation sequencing analysis, using a custom gene panel of known and candidate OI genes, was performed on a group of 166 OI patients and revealed seven individuals with a causative mutations located in the lethal regions. Patients' age, ranging between 3 and 25 years, excluded the expected fatal outcome. The identification of non-lethal cases caused by mutations located in lethal domains prompted us to determine the actual mortality caused by glycine substitutions mapping to lethal clusters and evaluate the distribution of all lethal glycine mutations across collagen type I genes, based on records deposited in the OI Variant Database. Finally, we identified six glycine substitutions located in lethal regions of COL1A1 and COL1A2 genes, of which four are novel. The review of all mutations in the dedicated OI database, revealed 33 distinct glycine substitutions in two lethal domains of COL1A1, 26 of which have been associated with a fatal outcome. Similarly, 109 glycine substitutions have been identified in eight lethal clusters of COL1A2, of which 51 have been associated with a fatal manifestation. An analysis of all glycine substitutions leading to fatal phenotype, showed that their distribution along collagen type I genes is not regular, with 17% (26 out of 154) of mutations reported in COL1A1 and 64% (51 out of 80) in COL1A2 corresponding to localization of the lethal regions.

Osteogenesis imperfecta tooth level phenotype analysis: Cross-sectional study

INTRODUCTION

Dental anomalies in Osteogenesis imperfecta (OI), such as tooth discoloration, pulp obliteration (calcified dental pulp space), and taurodontism (enlarged dental pulp space) vary between and within patients. To better understand the associations and variations in these anomalies, a cross-sectional study was designed to analyze the dental phenotype in OI patients at the individual tooth type.

METHOD

A cohort of 171 individuals with OI type I, III and IV, aged 3-55 years, were recruited and evaluated for tooth discoloration, pulp obliteration, and taurodontism at the individual tooth level, using intraoral photographs and panoramic radiographs.

RESULTS

Genetic variants were identified in 154 of the participants. Patients with Helical α1 and α2 glycine substitutions presented the highest prevalence of tooth discoloration, while those with α1 Haploinsufficiency had the lowest (<10%). C-propeptide variants did not cause discoloration but resulted in the highest pulp obliteration prevalence (~%20). The prevalence of tooth discoloration and pulp obliteration was higher in OI types III and IV and increased with age. Tooth discoloration was mainly observed in teeth known to have thinner enamel (i.e. lower anterior), while pulp obliteration was most prevalent in the first molars. A significant association was observed between pulp obliteration and tooth discoloration, and both were associated with a lack of occlusal contact. Taurodontism was only found in permanent teeth and affected mostly first molars, and its prevalence decreased with age.

CONCLUSION

The dental phenotype evaluation at the tooth level revealed that different genetic variants and associated clinical phenotypes affect each tooth type differently, and genetic variants are better predictors of the dental phenotype than the type of OI. Our results also suggest that tooth discoloration is most likely an optical phenomenon inversely proportional to enamel thickness, and highly associated with pulp obliteration. In turn, pulp obliteration is proportional to patient age, it is associated with malocclusion and likely related to immature progressive dentin deposition. Taurodontism is an isolated phenomenon that is probably associated with delayed pulpal maturation.

Implant-Prosthetic Restoration of a Patient with Osteogenesis Imperfecta: A Case Report

Osteogenesis imperfecta describes a group of genetic disorders that result from a defect in collagen type I and range in severity from a subtle increase in fracture frequency to death in the perinatal period. Osteogenesis imperfecta is mostly caused by mutations in the COL1A1 (17q21.33) and COL1A2 (7q21.3) genes. There have only been a few case reports of implant-prosthetic treatment for patients with osteogenesis imperfecta. These reports indicated that implants and augmentation procedures can be implemented in such patients. However, for patients receiving additional antiresorptive therapy, cautious approaches should be chosen and the risk of drug-associated osteonecrosis should be considered. The aim of this article is to report on the implant-prosthetic treatment of a patient with type I osteogenesis imperfecta.

Novel mutations in BMP1 result in a patient with autosomal recessive osteogenesis imperfecta

Background

Osteogenesis imperfecta (OI) is a rare heritable bone disorder that is characterised by increased bone fragility and recurrent fractures. To date, only 19 OI patients have been reported, as caused by BMP1 gene mutations, worldwide. Here, we report a patient with a BMP1 gene mutation to explore the relationship between genotype and phenotype, and the patient was followed up for 4 years.

Methods

Detailed clinical features were collected, and BMP1 mutational analysis was performed by next‐generation sequencing and Sanger sequencing.

Results

The patient had recurrent fractures, low bone mass, bone deformities and growth retardation but did not have hearing loss or dentinogenesis imperfecta. Next‐generation sequencing and Sanger sequencing revealed a heterozygous novel missense variant (c.362C>T in exon 3, p.Ala121Val) and a heterozygous novel deletion mutation (c.1252delA in exon 10, p.Ser418AlafsX22). The parents of the proband were heterozygous carriers of these mutations. The patient received regular weekly treatment of 70 mg oral alendronate for 3 years, and her BMD Z‐score for the femur significantly increased from −1.3 to 0.9 at L1‐4 and from −1.7 to −0.1. She had no fracture during 4 years of follow‐up.

Conclusion

We discovered two heterozygous novel mutations in an OI patient with BMP1 gene mutations, expanding the spectrum of gene mutations in OI.

Effects of treatment with a bone-targeted prostaglandin E2 receptor 4 agonist C3 (Mes-1007) in a mouse model of severe osteogenesis imperfecta

OBJECTIVE

Osteogenesis imperfecta (OI) is a heritable bone fragility disorder that is usually caused by mutations affecting collagen type I synthesis in osteoblasts. Bisphosphonates are widely used to decrease fracture rate but are only partially effective. Bone anabolic compounds, such as prostaglandin E2 receptor 4 (EP4) agonists may be an alternative treatment approach. Here we assessed the effect of Mes-1007, a novel bone-targeted EP4 agonist in Jrt mice, a model of severe OI.

STUDY DESIGN

Experimental study.

RESULTS

Male 8-week old wild type (WT) and OI mice were randomly assigned to 4 weeks of three intraperitoneal injections per week with Mes-1007 (25 mg per kg body mass), phosphate-buffered saline, zoledronate (5 μg per kg), or a combination treatment of zoledronate and Mes-1007. Treatment with Mes-1007 alone did not lead to higher trabecular bone volume per tissue volume (BV/TV) in the distal femur or lumbar vertebra 4 in either WT or OI mice. Treatment with zoledronate alone was associated with a significant increase in distal femur and vertebra BV/TV in both genotypes. In zoledronate-treated WT and OI mice, Mes-1007 increased bone formation rate in vertebral trabecular bone and had an additive effect on BV/TV. Vertebral BV/TV in OI mice that received zoledronate or Mes-1007/zoledronate combination treatment was similar to untreated WT mice (p = 0.25). At the femoral midshaft, Mes-1007/zoledronate combination treatment increased cortical thickness in both genotypes and led to higher periosteal diameter in OI mice. Three-point bending tests of femurs showed that Mes-1007/zoledronate combination treatment increased the stiffness, load at yield and maximal load in WT but not in OI mice.

CONCLUSION

Dosing Mes-1007 in combination with zoledronate improved the bone properties in a manner that is consistent with a mechanism of action of EP4 agonists on bone and additive to effects of anti-resorptives typified by zoledronate.

Survey of MRI Usefulness for the Clinical Assessment of Bone Microstructure

Bone microarchitecture has been shown to provide useful information regarding the evaluation of skeleton quality with an added value to areal bone mineral density, which can be used for the diagnosis of several bone diseases. Bone mineral density estimated from dual-energy X-ray absorptiometry (DXA) has shown to be a limited tool to identify patients' risk stratification and therapy delivery. Magnetic resonance imaging (MRI) has been proposed as another technique to assess bone quality and fracture risk by evaluating the bone structure and microarchitecture. To date, MRI is the only completely non-invasive and non-ionizing imaging modality that can assess both cortical and trabecular bone in vivo. In this review article, we reported a survey regarding the clinically relevant information MRI could provide for the assessment of the inner trabecular morphology of different bone segments. The last section will be devoted to the upcoming MRI applications (MR spectroscopy and chemical shift encoding MRI, solid state MRI and quantitative susceptibility mapping), which could provide additional biomarkers for the assessment of bone microarchitecture.

[Rehabilitation of orphan diseases in adulthood: osteogenesis imperfecta]

Osteogenesis imperfecta (brittle bone disease) is an orphan disease caused by a genetic mutation in collagen metabolism. Bone fractures are the most common symptoms; however, the clinical manifestation can vary widely. Additional features can include blue sclera, dwarfism, bone deformities, muscular weakness, scoliosis, hearing loss and hypermobility of joints. Most patients show a reduction of skeletal function. This leads to an increased risk of being unable to continue their former work and to participate in social life. A comprehensive treatment includes drug therapy, surgery and rehabilitation. This article gives an overview of the current status of rehabilitation in adult patients with osteogenesis imperfecta.

4-Phenylbutyric acid enhances the mineralization of osteogenesis imperfecta iPSC-derived osteoblasts

Osteogenesis imperfecta (OI) is a heritable brittle bone disease mainly caused by mutations in the two type I collagen genes. Collagen synthesis is a complex process including trimer formation, glycosylation, secretion, extracellular matrix (ECM) formation, and mineralization. Using OI patient-derived fibroblasts and induced pluripotent stem cells (iPSCs), we investigated the effect of 4-phenylbutyric acid (4-PBA) on collagen synthesis to test its potential as a new treatment for OI. Endoplasmic reticulum (ER) retention of type I collagen was observed by immunofluorescence staining in OI patient-derived fibroblasts with glycine substitution and exon skipping mutations. Liquid chromatography-mass spectrometry analysis revealed excessive glycosylation of secreted type I collagen at the specific sites in OI cells. The misfolding of the type I collagen triple helix in the ECM was demonstrated by the incorporation of heat-dissociated collagen hybridizing peptide in OI cells. Type I collagen was produced excessively by OI fibroblasts with a glycine mutation, but this excessive production was normalized when OI fibroblasts were cultured on control fibroblast-derived ECM. We also found that mineralization was impaired in osteoblasts differentiated from OI iPSCs. In summary, treatment with 4-PBA normalizes the excessive production of type I collagen, reduces ER retention, partially improves misfolding of the type I collagen helix in ECM, and improves osteoblast mineralization. Thus, 4-PBA may improve not only ER retention, but also type I collagen synthesis and mineralization in human cells from OI patients.

Case Report: Hyperplastic Callus of the Femur Mimicking Osteosarcoma in Osteogenesis Imperfecta Type V

BACKGROUND

Osteogenesis imperfecta (OI) type V is a rare form of OI which is often characterized by hyperplastic callus. Misdiagnosis is a possibility due to its rarity and because patients involved are mostly in adolescence, a predisposing age for osteosarcoma. Here, we report this case and aim to improve understanding of patients with OI type V and avoid misdiagnosis.

CASE PRESENTATION

A male, 14-year-old patient was admitted to Jiangxi Provincial People's Hospital affiliated to Nanchang University in August 2020 due to repeated fractures for more than 11 years and swelling in his right leg for more than 4 years. The patient was diagnosed with OI in 2014 due to repeated fracture and was treated with bisphosphonates. The swelling was accompanied by huge callus formation. Prior to admission to our hospital in 2016 osteosarcoma was suspected by imaging and pathology, and amputation was recommended. OI-V was confirmed after more than four years of follow-up and genetic diagnosis, and the affected limb was preserved.

CONCLUSION

The history of OI and lack of rapid progression suggested OI-V with a hyperplastic callus. Combined with genetic testing, the diagnosis was OI-V. Although the patient was at a predisposing age for osteosarcoma, diagnosis and treatment should be based on the medical history of the patient, imaging,and genetic testing, and sometimes even time-consuming retrospective observation.